[FFmpeg-devel] [PATCH] avfilter: Added siti filter

[Thilo Borgmann]

Am 24.01.22 um 12:10 schrieb Thilo Borgmann:
> Am 18.01.22 um 14:58 schrieb Thilo Borgmann:
>> Am 15.01.22 um 09:27 schrieb Paul B Mahol:
>>> On Sat, Jan 15, 2022 at 9:25 AM Paul B Mahol <onemda at gmail.com> wrote:
>>>
>>>>
>>>>
>>>> On Fri, Jan 14, 2022 at 5:22 PM Thilo Borgmann <thilo.borgmann at mail.de>
>>>> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> Am 19.01.21 um 05:49 schrieb Lynne:
>>>>>> Jan 19, 2021, 01:07 by borbarak at fb.com:
>>>>>>
>>>>>>> Calculate Spatial Info (SI) and Temporal Info (TI) scores for a video,
>>>>> as defined
>>>>>>> in ITU-T P.910: Subjective video quality assessment methods for
>>>>> multimedia
>>>>>>> applications.
>>>>>>>
>>>>>>> Update: Fixed bracket style.
>>>>>>>
>>>>>>
>>>>>> Thanks, looks much neater now.
>>>>>>
>>>>>>
>>>>>>
>>>>>>> I'm already adding the data to the frame's metadata, is the suggestion
>>>>> to remove the file option altogether?
>>>>>>>
>>>>>>
>>>>>> Yes. We want to avoid filters having their own file in/out options
>>>>> rather
>>>>>> than using generic ones.
>>>>>
>>>>> Updated the patch to apply to git HEAD.
>>>>> Removed file output.
>>>>> Made printing summary to console optional.
>>>>>
>>>>>
>>>>>>> +
>>>>>>> +#include "libavutil/imgutils.h"
>>>>>>> +#include "libavutil/internal.h"
>>>>>>> +#include "libavutil/opt.h"
>>>>>>> +
>>>>>>> +#include "avfilter.h"
>>>>>>> +#include "formats.h"
>>>>>>> +#include "internal.h"
>>>>>>> +#include "video.h"
>>>>>>> +
>>>>>>> +static const int X_FILTER[9] = {
>>>>>>> +    1, 0, -1,
>>>>>>> +    2, 0, -2,
>>>>>>> +    1, 0, -1
>>>>>>> +};
>>>>>>> +
>>>>>>> +static const int Y_FILTER[9] = {
>>>>>>> +    1, 2, 1,
>>>>>>> +    0, 0, 0,
>>>>>>> +    -1, -2, -1
>>>>>>> +};
>>>>>>>
>>>>>>
>>>>>> We have optimized assembly to apply 3x3 matrices. Check out
>>>>>> libavfilter/x86/vf_convolution.asm:ff_filter_3x3_sse4
>>>>>>   vf_convolution already applies a sobel filter that way. Maybe
>>>>>> look into sharing some DSP code with it?
>>>>>
>>>>> I checked a bit since I also want a common sobel for vf_edgedetect / my
>>>>> patch for vf_blurriness.
>>>>>
>>>>> For sobel, there is no direct asm implementation. We have a generic
>>>>> filter_3x3 with sse4 optimization. To use sobel with that, you'd need to
>>>>> run two times filter_3x3 plus one pass for gradient calculation.
>>>>>
>>>>> As another difference, this filter (SITI) does on-the-fly conversion to
>>>>> full-range pixel values during its sobel. While vf_edgedetect /
>>>>> vf_bluriness use an abbreviation for the gradients during its sobel. Which
>>>>> makes them both distinct enough not to fit into a general filter_3x3 or
>>>>> filter_sobel from vf_convolution easily (and more overhead). So I think
>>>>> it's not worth the effort to force them into a common function? (Especially
>>>>> since we don't have a sobel_sse4 or something)
>>>>>
>>>>> Patch without a common sobel attached.
>>>>>
>>>>>
>>>>
>>>> Violations of code style.
>>
>> Enhanced.
>>
>>
>>>> Also why filter description only shows SI part and TI part is missing?
>>
>> Mentioned.
>>
>> v2 attached.
> 
> Ping.

Going to apply soon if there are no more comments especially about the sobel functions.

-Thilo